Long-lifespan aqueous alkaline and acidic batteries enabled by redox conjugated covalent organic polymer anodes

Herein, we introduce a redox conjugated covalent organic polymer (p-HATN, HATN = hexaazatrinaphthylene) anode bearing HATN species for long-lifespan aqueous alkaline and acidic batteries. The p-HATN features intriguing superhydrophilicity and unique wide pH adaptability, while the conjugated network and amorphous cross-linked structure further endow p-HATN with improved electron transport, facile ion diffusion and superior acid-alkali tolerability. As a result, p-HATN exhibits fast surface-controlled redox activity and superior stability for K+ and H+ ions storage with remarkable capacity retentions in three-electrode cells (88% capacity retention in 13 M KOH over 30000 cycles; nearly 100% capacity retention in 0.5 M H2SO4 over 54000 cycles). Moreover, the assembled p-HATN//Ni(OH)2 cell with 13 M KOH and p-HATN//PbO2 cell with 0.5 M H2SO4 also achieve capacity retentions of 83% retention over 55000 cycles and 92% over 15000 cycles, respectively, outperforming most similar systems. This work sheds light on the rational design of advanced polymer anodes for long-lifespan alkaline and acidic batteries.